Prime Minister John Key is refusing to say if the New Zealand spies working in Afghanistan are operating under the command of an American agency such as the CIA.

Mr Key said yesterday he would not give any information to the public about the intelligence operatives his Government and Helen Clark's have secretly sent to the war.

This included whether they were working with the CIA - which faces allegations of abusing prisoners with interrogation techniques such as sleep deprivation, "insult slaps", water dousing and "walling" (slamming a detainee's head against a wall).

The Herald revealed this week that New Zealand intelligence agents are being used to help fight the Taleban.

They are separate from the country's military contribution and are most likely from the Security Intelligence Service and/or the Government Security Communications Bureau (GCSB).

NZ operatives were first sent to Afghanistan when Labour was in power. It, too, is refusing to comment.

That is despite Labour leader Phil Goff, a former Foreign Affairs and Defence Minister, now criticising National's decision to send the Special Air Service back in a combat role.

It is not known how many of the operatives are in Afghanistan or what role they have been playing in the war, although possibilities range from spying in the Afghan community to high-end communications interception.

Green MP Keith Locke said Labour and National owed the public a basic explanation of what the operatives were doing. "It will be worrying a lot of people what these agents are doing in New Zealand's name."

Official papers obtained by the Herald show personnel from two secret Government agencies are in the war.

Mr Locke said he was concerned GCSB staff could be using their expertise in electronic spying to help target American air strikes, which often caused civilian casualties.

Meanwhile, the Army is still deciding whether to send home three soldiers who posed beside a 2000-pound bomb and sent the photographs to an energy drink company here.

The soldiers photographed themselves writing the message, "Dear Taleban, enjoy this", on it.